1. Field of the Invention
The invention relates to a data network, and more particularly an apparatus and a method for performing an efficient address search in a switch network.
2. Description of the Related Art
Ethernet is a most typical protocol of LAN (Local Area Network) which occupies a very important portion in data networks. Ethernet is widely accepted in the industry already, and the application thereof reaches all kinds of data networks. At the present, since users are rapidly increasing and more various services are getting provided, bandwidth of a network is required to be wider than before. Providing wide bandwidth of a network enables converting from a repeater so called hub into a switch in a remarkably rapid speed. As compared to a repeater which shares a transmission medium, a switch efficiently uses only required sources from transmission means to receiver means thereby having a very rapid transmission speed.
Herein, “address search” means that an ethernet switch establishes required information to determine an output terminal, and collects and utilizes information for address. The address search is particularly important in an application in which management for address is highly required. Examples of the application include ARP (Address Resolution Protocol) management, NMS (Network Management System), RMON (Remote Monitoring) and etc.
In an example of an address searching method in an ethernet switch as shown in FIG. 1, a search memory interface (SMI) 6 receives a header and a port number of an input packet from a PCU (Port Control Unit) in each of port devices 2-0, 2-1, . . . , 2-7 to establish data about source address on a search memory, and determines an output port of each packet on the basis of the establish data.
However, in FIG. 1, since the 8 port devices are required to determine output ports by using the same search unit, the input packet of one port (device) only can be searched while the remaining ports (devices) are left to wait. Also, there are some structural problems in realizing a search logic required for a management switch, i.e., a switch which has a control unit for controlling an ethernet switch when the switch structure is a non-management switch, i.e. a switch which does not have a control unit for controlling an ethernet switch. An interface for sharing address data with other units was not defined also. In other words, in the non-management switch structure, the address structure is not suitably realized for a management switch.